Polar reformatting for ISAR imaging

Polar reformatting is a technique that has been developed and used extensively in spotlight SAR processing. The prerequisite for using this technique is to know the radar´s aspect angle, with respect to the target, for each pulse received by this radar. The key to using this technique for ISAR is to know the target´s rotational motion which in most cases is unknown. This paper will present a practical motion geometry for the rotational motion of a target, based on a parameterized model. A technique, based on this rotation model, to determine the rotation parameters, using measurements from the radar data itself, will be presented. A practical realization of this technique, using simplifications to the motion model, will be discussed and the effects of this simplification will be described